From: Ashish Sangwan Subject: Re: [PATCH v3] ext4: fix hole punch failure when depth is greater than 0 Date: Tue, 10 Jul 2012 10:05:28 +0530 Message-ID: References: <1341881004-1601-1-git-send-email-ashish.sangwan2@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Cc: linux-kernel@vger.kernel.org, linux-ext4@vger.kernel.org, lczerner@redhat.com, Ashish Sangwan , Namjae Jeon To: Ted Tso Return-path: Received: from mail-yw0-f46.google.com ([209.85.213.46]:65444 "EHLO mail-yw0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751198Ab2GJEf3 (ORCPT ); Tue, 10 Jul 2012 00:35:29 -0400 In-Reply-To: <1341881004-1601-1-git-send-email-ashish.sangwan2@gmail.com> Sender: linux-ext4-owner@vger.kernel.org List-ID: Please ignore the last sent mail. I will re-send the patch in new mail chain. Thanks, Ashish On Tue, Jul 10, 2012 at 6:13 AM, Ashish Sangwan wrote: > Whether to continue removing extents or not is decided by the return value > of function ext4_ext_more_to_rm() which checks 2 conditions: > a) if there are no more indexes to process. > b) if the number of entries are decreased in the header of "depth -1". > > In case of hole punch, if the last block to be removed is not part of the > last extent index than this index will not be deleted, hence the number of > valid entries in the extent header of "depth - 1" will remain as it is and > ext4_ext_more_to_rm will return 0 although the required blocks are not > yet removed. > > This patch fixes the above mentioned problem as instead of removing the > extents from the end of file, it starts removing the blocks from the > particular extent from which removing blocks is actually required and > continue backward until done. > > Signed-off-by: Ashish Sangwan > Signed-off-by: Namjae Jeon > Reviewed-by: Lukas Czerner > --- > fs/ext4/extents.c | 46 +++++++++++++++++++++++++++++----------------- > 1 file changed, 29 insertions(+), 17 deletions(-) > > diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c > index 91341ec..45ac45d 100644 > --- a/fs/ext4/extents.c > +++ b/fs/ext4/extents.c > @@ -2570,10 +2570,10 @@ static int ext4_ext_remove_space(struct inode *inode, ext4_lblk_t start, > { > struct super_block *sb = inode->i_sb; > int depth = ext_depth(inode); > - struct ext4_ext_path *path; > + struct ext4_ext_path *path = NULL; > ext4_fsblk_t partial_cluster = 0; > handle_t *handle; > - int i, err; > + int i = 0, err; > > ext_debug("truncate since %u to %u\n", start, end); > > @@ -2606,8 +2606,12 @@ again: > } > depth = ext_depth(inode); > ex = path[depth].p_ext; > - if (!ex) > + if (!ex) { > + ext4_ext_drop_refs(path); > + kfree(path); > + path = NULL; > goto cont; > + } > > ee_block = le32_to_cpu(ex->ee_block); > > @@ -2637,8 +2641,6 @@ again: > if (err < 0) > goto out; > } > - ext4_ext_drop_refs(path); > - kfree(path); > } > cont: > > @@ -2647,19 +2649,27 @@ cont: > * after i_size and walking into the tree depth-wise. > */ > depth = ext_depth(inode); > - path = kzalloc(sizeof(struct ext4_ext_path) * (depth + 1), GFP_NOFS); > - if (path == NULL) { > - ext4_journal_stop(handle); > - return -ENOMEM; > - } > - path[0].p_depth = depth; > - path[0].p_hdr = ext_inode_hdr(inode); > + if (path) { > + int k = i = depth; > + while (--k > 0) > + path[k].p_block = > + le16_to_cpu(path[k].p_hdr->eh_entries)+1; > + } else { > + path = kzalloc(sizeof(struct ext4_ext_path) * (depth + 1), > + GFP_NOFS); > + if (path == NULL) { > + ext4_journal_stop(handle); > + return -ENOMEM; > + } > + path[0].p_depth = depth; > + path[0].p_hdr = ext_inode_hdr(inode); > > - if (ext4_ext_check(inode, path[0].p_hdr, depth)) { > - err = -EIO; > - goto out; > + if (ext4_ext_check(inode, path[0].p_hdr, depth)) { > + err = -EIO; > + goto out; > + } > } > - i = err = 0; > + err = 0; > > while (i >= 0 && err == 0) { > if (i == depth) { > @@ -2773,8 +2783,10 @@ cont: > out: > ext4_ext_drop_refs(path); > kfree(path); > - if (err == -EAGAIN) > + if (err == -EAGAIN) { > + path = NULL > goto again; > + } > ext4_journal_stop(handle); > > return err; > -- > 1.7.10.4 >